pythonic way to rewrite an assignment in an if statement

Question

Is there a pythonic preferred way to do this that I would do in C++:

for s in str:
    if r = regex.match(s):
        print r.groups()

I r

Answer 1

How about

for r in [regex.match(s) for s in str]:
    if r:
        print r.groups()

or a bit more functional

for r in filter(None, map(regex.match, str)):
    print r.groups()